Cleaner air at home, without the guesswork.
Plain-language guides to purifiers, filters, detectors, and humidity. Every claim links to its source, and we tell you when the evidence is thin.
Hi, I'm Will. A Colorado wildfire took my family's home of 30+ years, and I have asthma. This site is what I learned trying to keep the smoke out. My story
Give me 90 seconds
Answer three questions and get the smoke CADR your room needs, the filter type that fits your problem, and the guides to read next.
Compared
Popular purifiers, ranked by certified smoke numbers
Not the room size on the box. This is the smoke CADR each model earned in certified lab testing, from ENERGY STAR's public database.
Winix
Tower XQ
- ~690 sq ft max room for smoke
- ~$83/yr electricity
Levoit
Core 600S
- ~590 sq ft max room for smoke
- ~$66/yr electricity
Coway
Airmega 400
- ~565 sq ft max room for smoke
- ~$62/yr electricity
Alen
BreatheSmart 75i
- ~555 sq ft max room for smoke
- ~$52/yr electricity
AirDoctor
AD4000
- ~555 sq ft max room for smoke
- ~$67/yr electricity
Blueair
Blue Pure 211+
- ~520 sq ft max room for smoke
- ~$60/yr electricity
Certified smoke CADR in cubic feet per minute from ENERGY STAR (Nov 2026). Room size uses the EPA two-thirds rule with 8-foot ceilings; electricity at 17ยข/kWh. Illustrations show the general shape only.
Read the transcript
When wildfire smoke rolls in, everyone says the same thing: stay inside and run an air purifier.
But does it actually work?
A 2025 public health review from Canada looked at 30 studies done during real smoke events.
On average, air cleaners cut indoor fine particles by about 56%.
But results ranged from 5% to 99%, depending on the home and the device.
In Seattle, during the 2020 fires, smoke got inside even with the windows closed.
Portable HEPA purifiers cut indoor levels by 48% to 78%.
Here's the catch. HEPA filters trap particles, not gases.
And only four studies measured health effects directly, with mixed results.
So size your purifier to the room, run it where you sleep, and keep spare filters on hand.
Every study is linked at IndoorAirLab.org.
Narration uses an AI voice.
Watch
Do air purifiers actually work for wildfire smoke?
What 30 studies found, in under a minute. New short videos every week on purifiers, filters, and smoke, each tied to a full guide with every source linked.
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One page covering carbon monoxide alarms, your furnace filter, humidity, and radon. Then The Clean Air Brief every other week: one sourced guide, one practical tip, and smoke alerts when fires flare up.
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Topics
We cover one topic in depth before moving to the next. Wildfire smoke is live; the rest are being researched now.
Wildfire smoke
What purifiers really do during smoke events, how to size one, and the cheap DIY option.
- Do air purifiers work for wildfire smoke?
- Air purifiers compared by certified numbers
- What size air purifier do you need?
- HEPA vs. carbon filters for smoke
- DIY box-fan cleaner vs. a store-bought purifier
- Air purifier standards around the world
HVAC and furnace filters
MERV ratings, what your system can handle, and how often to replace them.
2 guides publishedBasements
Moisture, mold, and musty air: what a dehumidifier fixes and what a purifier cannot.
Coming soonRadon tests and monitors
How to test, how to read results, and why filters do not remove radon.
Coming soonCarbon monoxide alarms
Where to install them and when to replace them. Purifiers do not remove CO.
1 guide publishedHumidifiers and dehumidifiers
Target humidity, sizing, and keeping the units clean.
Coming soonBabies and kids
Nursery air, quiet operation, and devices to avoid around infants.
Coming soonOlder adults
Simple equipment and protecting higher-risk people during smoke events.
Coming soonAllergies, pets, and cooking
Pollen, dander, and kitchen fumes: matching the fix to the problem.
Coming soonWildfire smoke guides
Each guide opens with how strong the evidence is, then links every source.
Do air purifiers work for wildfire smoke?
What field studies show about PM2.5 reduction, and what is still uncertain.
Air purifiers compared by certified numbers
Certified smoke CADR, room size, and yearly electricity for 10 popular models, plus what independent smoke tests found.
What size air purifier do you need?
The smoke CADR rule, with a room-size table.
HEPA vs. carbon filters for smoke
Particles, gases, and how much to trust the marketing claims.
DIY box-fan cleaner vs. a store-bought purifier
What EPA lab tests found, plus noise, safety, and filter changes.
Air purifier standards around the world
HEPA grades, CADR units, China's CCM rating, and research from Canada, Australia, and Southeast Asia.
Guides and resources
Not sure where to start? Every guide is free, plain-language, and linked to its sources.
Wildfire smoke resources
Does it fit your room, and what will it cost?
Move the sliders to check room coverage and the 5-year cost of purchase, filters, and electricity. Specs are manufacturer-reported and not yet verified by us. Coverage uses the EPA and ENERGY STAR rule: smoke CADR at least two-thirds of floor area, 8-foot ceilings.
5-year total = price + 4 years of filters (the first set comes with the unit) + electricity at typical power draw.
Sources on every page
Guides cite peer-reviewed studies, public health agencies, and published standards, with links you can check.
Evidence ratings, not hype
Each guide rates how strong the evidence is for its main claims, including where it is weak.
No paid rankings
Commissions never change what we recommend. Our own testing program is being set up, and we will publish the method first.
Why I started IndoorAirLab
My family lived in the same house in Colorado for more than 30 years. A wildfire took it. The fire ended, but the smoke didn't: just about every summer since, it's drifted in from fires in the Rockies, from Canada, and from places hundreds of miles away.
I have asthma, so I went looking for what actually helps. Mostly I found marketing. So I started reading the studies and the certified test data myself, and writing down what I learned in plain English. That's what this site is.
Common questions
Will an air purifier fix a musty basement?
Usually not on its own. Musty air generally comes from moisture, so the fix starts with finding the water source and controlling humidity. A purifier can help with airborne particles once moisture is under control.
Does a HEPA filter remove radon or carbon monoxide?
No. Both are gases that HEPA filters do not capture. Radon calls for testing and, if levels are high, professional mitigation. Carbon monoxide calls for working CO alarms and well-maintained fuel-burning appliances.
Do I need a bigger purifier than my room size suggests?
If you have smoke, pets, or allergies, more CADR cleans the air faster and lets you run the unit at a quieter speed.
Why is this a .org if you earn commissions?
We chose the name for the mission, not to suggest we are a charity. IndoorAirLab.org is an independent, for-profit site funded by affiliate commissions.